The Relative Amounts of the Collagen Chains α1(I), α2 and α1(III) in the Skin of 31 Patients with Osteogenesis Imperfecta

Abstract

1. The relative amounts of type III and type I collagen, determined as the ratio of their constituent alpha 1(III) and alpha 1(I) chains, have been measured by interrupted electrophoresis of pepsin extracts of skin collagen from 31 patients with osteogenesis imperfecta of varying severity, and from six clinically unaffected family members. In 18 patients the ratio of the alpha 1(I) to alpha 2 chains of type I collagen has also been measured. 2. In the 15 patients with osteogenesis imperfecta classified as mild or the 18 with type I disease the ratio alpha 1(III)/alpha 1(I) was significantly increased (P less than 0.001) and the ratio alpha 1(I)/alpha 2 significantly decreased (P less than 0.005) compared with age-matched control subjects. 3. In three infants with lethal (type II) osteogenesis imperfecta the ratio alpha 1(III)/alpha 1(I) was normal, contrasting with the high ratio observed by others in fibroblast cultures from some apparently similar patients. 4. The ratio of alpha 1(I)/alpha 2 and of alpha 1(III)/alpha 2(I) was increased in both clinically normal parents of a child with severe disease, and in the mother of two children with osteogenesis imperfecta (one lethal and one severe) the ratio alpha 1(III)/alpha 1(I) was increased. 5. In the remaining patients with severe bone deformity (types III and IV) the relative amounts of the different collagen chains varied. 6. These data support previous suggestions that mild or type I osteogenesis imperfecta results from a generalized inability to form sufficient type I collagen, the predominant collagen of adult bone, and imply that in many cases this may result from defective production of the alpha 1(I) chain rather than of the alpha 2 chain. Some patients with severe disease demonstrate a similar defect; but in the remainder other abnormalities of collagen or connective tissue maturation are presumably involved.

Variations in the serum concentration and urine excretion ofα 2HS-glycoprotein, a bone-related protein, in normal individuals and in patients with osteogenesis imperfecta

“…It is likely that this clinical heterogeneity reflects differences in the fundamental molecular abnormalities. At present, there is growing evidence that some of these disorders result from defects in the synthesis or maturation of collagen [11,12]. All but one of the high values for a2HS-glycoprotein in plasma were found in patients with Sillence's type I OI; in part, this may reflect the total number of patients with this type.…”

Heterogeneity of osteogenesis imperfecta. Biochemical and morphological findings in a case of type III according to Sillence

“…In a comment, Spranger pointed out that there is a report on an a girl who has now to be classified as OI type III, while her newborn brother has to be diagnosed as subtype IIB [6]. These findings were later confirmed in intact bone [5,10,23] and now appear characteristics of this OI type. As early as 1920, Bauer suggested that OI was a systemic disease of the connective tissue due to a disordered synthesis of collagen [1,2].…”

The Use of Type I and Type III Injectable Human Collagen for Dermal Fill: 10 Years of Clinical Experience in China

“…The collagen concentration was measured as previously described. 12 Type I and type III injectable human collagen passed the required bacteriology, virology, and pathology tests. Type I and type III injectable human collagen is packaged in 2-mL syringes in a physiological saline buffer solution containing 0.3% lidocaine at a pH of 7.2.…”